Array weight removal
1. Set
Array.from(new Set(arr))
/* perhaps */
[...new Set(arr)]
2. Map
3. Array.prototype.indexOf Method
4. Array.prototype.includes Method
5. Array.prototype.filter Method
function unique(arr) {
return arr.filter(function(item, index, arr) {
// If the first index of the current element in the original array is equal to the current index , Returns the current element
return arr.indexOf(item, 0) === index;
});
}
6. Array.prototype.reduce Method + Array.prototype.includes Method
function unique(arr){
return arr.reduce((prev, cur) => prev.includes(cur) ? prev : [...prev, cur], []);
}
7. Array.prototype.sort Method
